1. Technical Field
The present disclosure relates to a method of manufacturing toner.
2. Description of Related Art
In an electrophotographic or electrostatic image forming apparatus, an electrostatic latent image is formed on a photoreceptor and the electrostatic latent image is developed into a toner image. The toner image is transferred onto a recording medium such as paper and fixed thereon by application of heat and pressure.
To meet recent demand for high-quality image, toner has been developed to have a smaller particle size so that latent images can be more precisely reproduced. Toner has been also developed to have environmentally-resistant chargeability so that latent images can be reliably developed into toner images regardless of temperature and humidity conditions.
Polymerization methods producing toner in aqueous media have been proposed. Polymerization methods generally produce a toner having a small size, a narrow size distribution, and substantially spherical shape, while consuming large amounts of time, water, and energy. For example, a polymerization method requires a long time period for completing the polymerization and another time period for separating the resultant toner particles from solvent. The toner particles are repeatedly subjected to washing and drying while consuming water and energy.
Japanese Patent Nos. 3786034 and 3786035 and Japanese Patent Application Publication No. 57-201248 each propose a method called injection granulation method for manufacturing toner. In injection granulation methods, raw materials of toner are dissolved or dispersed in an organic solvent and the resulting liquid is atomized. The atomized particles are dried into toner particles. Because water is not used, injection granulation methods do not need washing and drying processes, which results in drastic reduction of consumed amounts of time and energy.
In injection granulation methods, some atomized particles may coalesce before the organic solvent is removed therefrom and the coalesced particle is dried into toner particle. As a result, the resulting toner particles have a wide size distribution. Because the atomized particles are spherical due to surface tension, the resulting toner particles are also spherical. Spherical toner particles are difficult to remove when remaining on a photoreceptor.